In a call center, many types of private information are exchanged between agent and customers (for example, credit, card information, personal identification numbers (PINs), telephone numbers, electronic mail (e-mail) addresses, social security numbers (SSNs), etc.). Challenges exist in the ability to automatically protect sensitive information in an audio file and expose it to a particular person depending on his or her role. An example of the access privilege can be as follows.
Role:Private information to be protected:IT AdministratorCC number, PIN number, verification number,email id, telephone number, AddressQuality ExpertCredit card number, PIN number, verification numberAuditornone
Existing approaches of protecting audio content include offline encryption (for example, compressing the entire file (naive compression) using an advanced encryption standard (AES) encryption scheme or a data encryption standard (DES) encryption scheme). Other existing approaches include scrambling (for example, permuting a signal in time domain or distorting a signal in frequency domain and then using inverse filter banks), and selective encryption. Additional existing approaches include degrading information reproduction without key and protecting broadcast content by encrypting the packets at transmitter end and decrypting them at the receiver end.